In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option. If a sentence is free from error, select No Error.
Many firms fail because when they begin (1)/ exporting, they have not research the (2)/ target markets or have not planned enough. (3)/ No error (4)

Answer

2

Explanation

Here, Present perfect (= subject + have/has + not + `V_`) i.e. exporting, they have not researched the ..... should be used. Other clause is in Present Perfect.